American cinematographer. (1954)

secret of good, flutter-free sound re¬ cording. The one we have installed was made to our special order, although any good, heavy, well-balanced flywheel such as commonly used in 16mm sound projectors will work just as well. Our flywheel is free floating, and is not con¬ nected to any motor, belt, pulley or any other component of the recorder. The travel of the magnetic film is all that turns it. The wheel is inside the recorder cabinet, just back of the panel, with its shaft protruding. Mounted on this shaft is a hub over which the film rides, and which may be seen in Fig. 3, just to the right and slightly below the recording head. The function of the flywheel is to smooth out the flutter and vibration normally introduced in the magnetic film as it engages the film sprocket. The better the flywheel is engineered, the more efficient it will operate. Besides the stabilizing effect imparted to the moving film by the flywheel, there is need for still other flutter retarders. Professional magnetic recorders usually employ the patented Davis Flutter Supresser. We have simply used a curved surface in the path of film travel, just before the film engages the drive sprocket, and which is covered with felt. This simple gagdet, which may be seen to the left of the takeup reel in Fig. 3, eliminates a surprising amount of flutter and vibration, yet puts little if any strain on the film. And this was one of the major problems that confronted us — how to introduce flutter suppressors which would do the work expected yet not induce undue pull on the film. For if there is too much pull on the film anywhere along the forward path, the sprocket teeth will tear the perforations and render the film worthless. This is not as important during recording as it is in projection of the film, where re¬ peated U6e would soon ruin the mag¬ netic film. By comparison, the film is subject to only moderate strain during recording because it passes through the recorder only once, or twice at the most; for this reason, we have loaded the recorder with pressure in the path of film travel. The first pressure pads, plus the pressure ap¬ plied under the two heads, plus the in¬ ertia of starting the flywheel, plus the pull of the felt-covered curved track is just about all the film will take. We have run the same film through the recorder as many as 30 times without even the slightest damage evident in the perforations. As for other components in the re¬ corder, the sprocket wheel used is one commonly used on an 8mm movie pro¬ jector. Originally, it had 16 teeth (for 8mm film perforations), so it was nec¬ essary to file off every other tooth, leav( Continued On Page 41) i incident light exposure meter ,d for Better Flash Pictures! " The Standard Of The Studies" The needle indicates the proper "f" stop for perfect color exposure No need to set for film speed, no need to use or look at the computer when shooting in color — the C0L0R-MATIC Control does the job for you — quickly, easily, beautifully. PERFECT COLOR EXPOSURES 0A Ample at) HtSSSS (M/'inaKc CONTROL For Simplified Direct Reeding When Taking Color Mm COLOR -NIATIC Control provides the sim¬ plest, most accurate way of taking color pictures ever devised. No other meter can match the NORWOOD DIRECTOR for versatility — for color, black-and-white, stereo, still, movie. In addition to COLOR-MATIC Control, the new model features a new dial with' larger, easier-to-read numbers. Of course, the PHOTOSPHERE and other famous features have been retained. And still only $32.95, with Photosphere, Photodisk, Photogrid and COLOR-MATIC Control. See Your Photo Store, or Write For Literature to DIRECTOR PROD¬ UCTS CORP., 570 Fifth Ave., New York 36. With COLOR-MATIC Control you set the camera at l/50th second You point the Photosphere at the camera position American Cinematocrapher January, 1954 39